Forging die lubrication

ABSTRACT

A die for a forging operation, especially isothermal forging, is formed having grooves thereon to act as reservoirs for holding a lubricant for lubricating the die during operation. While the lubricant can be put in the grooves originaly by various means, one means for maintaining lubricant in the grooves during a forging operation where a plurality of billets are forged in succession is to have the billet covered by the lubricant, then each billet would leave some lubricant in the grooves for the next forging while pushing some out to use for its own forging operation.

[ Dec. 25, 1973 MM r in forged in suc- 9/1938 Switzerland..... 10/1961 Great ABSTRACT A die for a forging operation, especially isothermal forging, is formed having grooves thereon to act as ma n aiy n .l 'wm in t e? qy s t m 8 0 5 Claims, 3 Drawing figures FOREIGN PATENTS OR APPLICATIONS Primary Examiner-Charles W. Lanham Assistant ExaminerE. M. Combs Attorney-Jack N. McCarthy reservoirs for holding a lubricant for lubricating the die during operation. While the lubricant can be put in the grooves originaly by various means, one means for operation whelea plurality of billets are cession is to have the billet covered by the lubricant, then each billet would leave some lubricant in the grooves for the next forging while pushing some out to use for its own forging operation.

141,530, May 10, 1971,

B21j 3/00, B2lj 1/06, 3211' 13/02 Sejoumet et Lyon..... Sejoumet Roy L. Athey, North Palm Beach, Fla.

[7 3] Assignee: United Aircraft Corporation, East Hartford, Conn.

Apr. 6, 1973 Related U.S. Application Data [62] Division of Set.

abandoned.

References Cited UNITED STATES PATENTS United States Patent Athey FORGING DIE LUBRICATION [75] Inventor:

22 Filed:

21 Appl. No.: 348,569

51 int.

[58] Field of Search FORGING DIE LUBRICATION This is a division of application Ser. No. 141,530, filed May 10, 1971, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to the lubricating of dies and particularly to those which are not easily accessible.

SUMMARY OF INVENTION A primary object of the present invention is to provide means for lubricating dies without excessive delay to a forging cycle. This is especially useful where a forging operation involves processing a plurality of billets in succession where the-dies are not easily accessible, for example in an apparatus where it is desirable to maintain a predetermined atmosphere around each forging. This may involve the desirability of maintain ing a temperature around a billet, an inert gas or a vacuum.

In accordance with the present invention, a groove having an angular or substantially V-shaped crosssection is placed on a die surface to act as a lubricant reservoir.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a forging apparatus having heat means therearound for heating the dies while they are in operation.

FIG. 2 is an enlargement of a portion of the die surface marked A in FIG. 1.

FIG. 3 is an enlargement showing a section of the forward edge of a billet at one point in time after being heated while it is being compressed and moved across the die face.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIG. 1, an upper forging die 109A is shown along with a mating lower forging die 1108. A billet 252 is shown positioned between the surfaces of the two forging dies as the forging process begins. A susceptor 146A is located around the upper die as is an induction heating element 136A and a susceptor 1468 is located around the lower die as is arr-induction heating element 1368. Up and down movement of each susceptor and heating element is controlled by an actuating unit fixed to arms 100. For details of the apparatus for forging see co-pending application Ser. No. 141,528, filed May 10, 1971, to Joseph B. Moore and Roy L. Athey for APPARATUS FOR FORGING, now U.S. Pat. No. 3,698,219.

The face of a die which would be contacted by the heated billet 252 during operation of the forging apparatus has grooves 2 formed thereon which would be located one after the other in the direction of the flow of the billet. A cross-section through a groove (see FIG. 2) shows that the side of the groove located near the center of the die extends substantially perpendicular to the die surface while the other side is tapered. As shown in FIG. 2, the grooves 2 could be a series of concentric circles or be formed by a spiral, similar to that of a phonograph record. The grooves act as a reservoir for a dry lubricant 4. Graphite or boron nitride can be used when the forging is done in an inert atmosphere.

This means of lubricating a die surface is particularly useful where an apparatus for forging is being used wherein a plurality of billets are to be forged in a production line manner and it is desirable to maintain a particular type of atmosphere in the area where the forging is being done. For example, if a forging is being made under a high temperature and an inert gas, it would be desirable if the temperature and gas could be maintained in the area without being released between forgings. In this case, in practice, the die surfaces having the grooves 2 would be covered by a lubricant before the start of the forging cycle. The lubricant can be mixed with water or alcohol, for example, and then painted or sprayed on. Each succeeding forging billet 252 would be lubricated prior to being placed in the forging apparatus so that a coating 6 of the lubricant would appear over the entire surface thereof. This would help to replenish the lubricant in the reservoir 4 as some of the lubricant is pushed out of the reservoir ahead of the heated billet being forged into its new configuration (See FIG. 3).

In a die construction built, the space s" between the grooves was 0.01 inches and the width w" of the groove was 0.01 inches. The depth d along the perpendicular side was 0.005 inches. The width w" of the groove was double the depth d of the perpendicular side.

During a forging operation in an inert atmosphere, die construction referred to above was used and the lubricant used was boron nitride. The metal forged was INIOO and nine consecutive forgings were made without directly applying more lubricant to the grooves on the surface of the die.

I claim:

1. A method for lubricating a die in a forging operation using an upper and lower die member, including the steps of:

a. placing a plurality of concentric grooves spaced around the center of the face of said die member;

b. placing a lubricant in said grooves;

c. placing a billet between said forging die members at the center of said die'members and said grooves thereon;

d. applying a converging force on said die members to flow said billet therebetween;

e. flowing said billet outwardly in a radial direction transversely over the concentric grooves one after the other; and,

f. pushing some of the lubricant out of each groove by the forward edge of the flowing billet extending into each groove as it passes thereover to lubricate ahead of the flowing billet.

2. A method for lubricating a die in a forging operation as set forth in claim 1 including the steps of:

g. applying heat to said die members while applying said converging force;

h. applying heat to said billet while applying said converging force.

3. A method for lubricating a die in a forging operation as set forth in claim 1 including the steps of:

g. coating said billet with a lubricant;

h. replacing the lubricant pushed out of the grooves by'the flowing billet with the lubricant coated on said billet.

4. A method of lubricating a die in a forging operation as set forth in claim 1 wherein step (a) each groove is formed having a cross section such that the outer side of the groove away from the center of each die member is tapered and the side of the groove on the inner side of said groove near the center of the die member is substantially perpendicular to the face of said die member.

5. A method of lubricating a die in a forging operation as set forth in claim 4 wherein the radial width of the groove is made 0.01 inches, the depth along the substantially perpendicular side is made 0.005 inches,

and the space between thegrooves is made 0.01 inches. I l l 

1. A method for lubricating a die in a forging operation using an upper and lower die member, including the steps of: a. placing a plurality of concentric grooves spaced around the center of the face of said die member; b. placing a lubricant in said grooves; c. placing a billet between said forging die members at the center of said die members and said grooves thereon; d. applying a converging force on said die members to flow said billet therebetween; e. flowing said billet outwardly in a radial direction transversely over the concentric grooves one after the other; and, f. pushing some of the lubricant out of each groove by the forward edge of the flowing billet extending into each groove as it passes thereover to lubricate ahead of the flowing billet.
 2. A method for lubricating a die in a forging operation as set forth in claim 1 including the steps of: g. applying heat to said die members while applying said converging force; h. applying heat to said billet while applying said converging force.
 3. A method for lubricating a die in a forging operation as set forth in claim 1 including the steps of: g. coating said billet with a lubricant; h. replacing the lubricant pushed out of the grooves by the flowing billet with the lubricant coated on said billet.
 4. A method of lubricating a die in a forging operation as set forth in claim 1 wherein step (a) each groove is formed having a cross section such that the outer side of the groove away from the center of each die member is tapered and the side of the groove on the inner side of said groove near the center of the die member is substantially perpendicular to the face of said die member.
 5. A method of lubricating a die in a forging operation as set forth in claim 4 wherein the radial width of the groove is made 0.01 inches, the depth along the substantially perpendicular side is made 0.005 inches, and the space between the grooves is made 0.01 inches. 